Exchange columns are typically employed for heat or mass transfer operations, such as, but not limited to, distillation, absorption, stripping, rectification or other chemical or process treatments between a gas and a liquid, such as when a downwardly flowing liquid in a column engages with an upwardly flowing gas to provide an exchange relationship between the gas and liquid. Such heat exchange or mass transfer exchange columns contain, vertically arranged and spaced-apart, various mass transfer beds or sections, which sections or beds would be composed, for example, of a plurality of random packing such as rings, saddles or other such loosely filled, nonstructured packing, or structured packing, such as a designed, corrugated, contacting metal, ceramic or plastic sheets placed in an angle to each other. The random or structured packing may be employed in separate packed beds or mixed in packed beds, and usually there would be a plurality of packed beds vertically arranged throughout the exchange column with space between the beds.
In the column space between the mass transfer or bed sections, there is generally disposed beneath a packed bed or section a liquid collector, whose purpose is to collect the downwardly flowing liquid from the upper bed or section and to direct the liquid into a center channel of a separate, spaced-apart, liquid distributor beneath the liquid collector. For example, the collector would be disposed directly beneath the lower section of the packed bed or section and would comprise, for example, a plurality of upwardly-extending, parallel vanes and separate channels, so that the downwardly flowing liquid would flow onto the surface of the vanes and into the channels and then be directed to a collector ring about the internal diameter of the column and then downwardly in pipes to the center-most distribution trough of a separately positioned and spaced-apart liquid distributor for the collected liquid.
Such exchange columns include a separate liquid distributor placed below the liquid collector and designed to receive the outflow from the liquid collector within the center trough or channel of the liquid distributor. Usually, such liquid distributors would provide a central channel, open at the top and having a plurality of spaced-apart, parallel, lateral, troughs extending outwardly therefrom and with the central channel and lateral troughs providing for the generally uniform distribution of the collected liquid onto the upper surface of the packed bed or section usually directly below the liquid distributor. The liquid distributors are designed to provide for the generally uniform flow over the entire cross-sectional area of the lower packed bed or section, through, for example, the use of drip tubes emanating from the side of the lateral channels, or splash or drip plates, or holes in the side of the channel or holes in the bottom of the channel, or any combination thereof. The employment of separate, vertically arranged, spaced-apart, vane-type collectors and separate, spaced-apart, downstream, liquid distributors in exchange columns are well-known and well-utilized.
It is desired to provide for a new and improved, compact, integral liquid collector-distributor in an exchange column which permits a reduction in height of the exchange column or saves internal column space, reduces the cost of manufacturing and installation of the collector-distributor device and otherwise provides for additional advantages in the efficiency and method of operating the exchange column.